The biggest questions facing Jurgen Klinsmann, USMNT in 2016

After the year the United Stats men's national team has had, it might be best to look ahead to 2016.

Because what a strange year 2015 was, even by the Yanks' mercurial standards.

A lone win from the first four games to start the year, followed by yet another 2-0 victory over archrivals Mexico. Then came rollicking, come-from-behind upsets of the Netherlands and Germany, and three more consecutive wins after that made for a nine-game unbeaten run in all. But things had frayed by the end of that spell, and the Gold Cup would end in a premature semifinal ouster to underdogs Jamaica. Starting then, the U.S. lost five of six – once in extra time and once on penalties – including a playoff against Mexico for a spot at the 2017 Confederations Cup.

Jurgen Klinsmann and his men got their acts together in time for World Cup qualifying, though. In spite of rather unfathomably going behind early to Saint Vincent and the Grenadines, the part-timers were routed 6-1 last Friday. On Tuesday, the Americans traveled to Trinidad and Tobago and played the rising Caribbean power to a mirthless 0-0 stalemate.

For now, Klinsmann's job seems safe, having gained passable results in the most recent games. Many had wondered if a stumble against one of the ampersand opponents might bring his four-year tenure to an end well before his contract expires in 2018. Such had been the depths of the morale around American soccer and the national team's stubbornly unconvincing showings.

Perhaps the satisfaction of gaining four points out of six against less talented teams is a sign of diminished expectations under Klinsmann. All the same, it's hard to imagine him being displaced before the pair of qualifiers against Guatemala in March.

For better or worse (hint: better), 2015 is over now. And 2016 promises to be a big year with another slate of World Cup qualifiers and the one-off Copa America Centenario on home turf, pitting the USA against all of South America as well as its own region.

Before then, however, there are many questions to find answers to.

Can the back line stabilize?

Klinsmann wedged a stick in the revolving door that has been his back line since the 2014 World Cup by going back to a Matt Besler-Geoff Cameron pairing in central defense in November. And much like in the last cycle, they proved a sound and steady foundation to the back four. This underscored that there was never any need to replace them with the shaky duo of Ventura Alvarado and John Brooks during the Gold Cup – especially considering that Besler and Cameron, at ages 28 and 30 respectively, aren't in danger of aging out just yet.

Tim Ream looked solid enough at left back in the most recent games, and Michael Orozco didn't do anything to question his spot at right back against Trinidad and Tobago. Those two are central defenders by trade, however, and offered little going forward.

Still, it would be helpful for the team if Klinsmann finally settled on a first-choice back line, rather than forever cycle players through. Certainly, specific adjustments can be made to opponents, but few teams have ever achieved very much with an insecure defense.

For how long should Howard and Guzan rotate?

Goalkeepers Tim Howard and Brad Guzan are model professionals and have carved out fine careers in the Premier League. As such, they are worthy successors to Brad Friedel and Kasey Keller, the greatest goalkeepers North America has ever produced. Through the World Cup, there was a clear pecking order. Howard was the top man; Guzan his reliable understudy.

Howard's return from his year-long sabbatical has created something of an unsettled situation in goal, though. Guzan retained the job through the Mexico playoff, but they have rotated since, with Howard tending the nets against Costa Rica and Trinidad and Tobago while Guzan got the Saint Vincent game.

Neither man is likely to make a problem of this arrangement. And, by all accounts, they get along well. But at some point, the turnover behind them could become problematic for the defenders. Just as he did when he rotated Oliver Kahn and Jens Lehman in goal as Germany manager, Klinsmann will eventually have to choose. And when he does, it's worth remembering that Guzan is 31 and Howard will turn 37 before the March qualifiers, even if he is aging well.

What part will Clint Dempsey play?

The one-time captain was curiously omitted from the roster for these qualifiers, and he was particularly missed against Trinidad and Tobago when the Americans lacked someone to connect the dots and provide a spark in the final third – the very job Dempsey excels in.

Klinsmann explained his snub of the man with 48 international goals – who could yet eclipse Landon Donovan's record of 57 – by claiming that he wanted to give younger strikers a chance (although he called up 34-year-old Alan Gordon, who is two years older than Dempsey.)

It's hard to tell if Dempsey will still be around at the World Cup in 2018. He remains productive and influential with the Seattle Sounders, but will Klinsmann continue to lean on a player who used to be one of his obvious favorites? Or will Dempsey be shoved out like Donovan, even though he remains effective?

Can Darlington Nagbe be fit into the midfield?

There was much anticipation when the Liberian-born Portland Timbers attacking midfielder finally got his American citizenship. And, unlike most, he lived up to the hype in two sharp appearances. For a country that's craved a playmaker for more than a decade, that's an exciting development.

Klinsmann deployed him as a central midfielder and on the left flank. But Nagbe would probably be at his best in a role behind the striker(s). That might require the German head coach to tinker with his midfield, as he seems in no mood to break up his central partnership of Michael Bradley and Jermaine Jones just yet. Find a spot for Nagbe to fit in, however – perhaps in front of those two, even if it comes at the expense of a striker – and the payoff could be big. Especially if it allows Bradley to stay deeper and pull the strings at the base of the attack and frees Jones from having to cover so much vertical territory.

Will roles be defined?

One of Klinsmann's more maddening traits has been his habit of shuffling players all over the field, often into positions they aren't accustomed to playing with their club teams. Fabian Johnson has been regularly deployed at right back, left back and left wing. DeAndre Yedlin plays right back and on the right wing. Gyasi Zardes has been put on either flank and up front.

While there's certainly value in having multifunctional players, these younger members of the program would benefit from having a set position to make their own. They all seem stuck in the gray area between roles. Their inability to focus on a specific skill set for one position has made for plenty of incomplete performances. A little more positional clarity would go a long way in resolving some of the issues this team has with shape, possession and precision in the attack.

Leander Schaerlaeckens is a soccer columnist for Yahoo Sports. Follow him on Twitter @LeanderAlphabet.